1. Field of the Invention
The present invention relates to an ink jet recording apparatus and an ink jet recording method.
2. Description of the Related Art
As inks used in ink jet recording, generally, dye inks in which water-soluble dyes are dissolved in aqueous medium have been widely used. In recent years, pigment inks formed by dispersing pigments having higher water-fastness and higher lightfastness than dyes in aqueous medium have also been provided. Examples of the pigment inks include a pigment ink formed by dispersing a pigment using a dispersant in an aqueous medium, and a pigment ink having a self-dispersion pigment as a coloring material, the self-dispersion pigment having a hydrophilic group bonded to its surface to facilitate its dispersion, and the self-dispersion pigment being dispersed in an aqueous medium.
In exemplary proposals, a self-dispersion pigment is selected as a coloring material for a black ink used to record characters and drawings on plain paper because it allows achievement of high image density and excellent character quality (Japanese Patent Laid-Open Nos. 2000-198955 and 2001-089688).
Furthermore, as to a pigment ink used to form an image on a special recording medium, such as glossy paper having a coated surface, it has been considered to be effective from the viewpoint of abrasion resistance and glossiness to use a polymer-dispersion pigment as a coloring material, the polymer-dispersion pigment being dispersed using a polymer as a dispersant. Moreover, in recent years, in order to obtain high image quality regardless of the type of recording medium, proposals have been made in which a plurality of pigment inks of different pigment dispersion types are combined. For example, in one proposal, two types of ink, namely, a polymer-dispersion pigment ink in which a polymer-dispersion pigment is used as a coloring material, and a self-dispersion pigment ink in which a self-dispersion pigment is used as a coloring material, are provided in an ink jet recording apparatus to form an image (Japanese Patent Laid-Open No. 2003-213180).